1. Field of the Invention
The present invention relates to a machine tool that includes a movable nozzle for cleaning the inside of a machine.
2. Description of the Related
On a machine tool, a cover is provided so that chips generated during machining or cutting fluid used for machining do not scatter around the machine tool. Although the cover can prevent chips and cutting fluid from scattering around the machine tool, chips may adhere to the inner surface of the cover and accumulates thereon as machining is continued.
As a technique for preventing such accumulation of chips on the inside of a cover, for example, Japanese Utility Model Application Laid-Open No. 05-067446 discloses a technique in which a scraper is provided on a saddle moving back and forth during a machining cycle, a chip washing liquid supplying pipe is provided on an oil pan, and a nozzle is provided on this chip washing liquid supplying pipe, wherein the scraper collects chips with the saddle moving back and forth and liquid discharged from the nozzle washes out the chips. Furthermore, Japanese Utility Model Application Laid-Open No. 05-029655 discloses a technique in which a pipe including a nozzle hole for discharging washing liquid therefrom is fixed on a saddle, and the pipe is moved with the saddle moving back and forth to wash out chips in a wide range.
However, although both of the prior art techniques described above wash out chips accumulated on the inside of a cover, the orientation of the nozzle is fixed and thus the flow of the chip washing liquid is stationary. With this, stagnation is easily generated in the flow of the liquid and a chip accumulation part is easily generated. Furthermore, the orientation of the nozzle cannot be freely changed in accordance with the machining conditions.
Furthermore, Japanese Utility Model Application Laid-Open No. 03-026451 discloses a technique in which a rotation controller is assembled to a showering device arranged on the ceiling side of a machining area of a machine tool body and the rotation controller automatically adjusts the orientation of a showering nozzle attached to the showering device during machining of a workpiece in accordance with a command programmed in advance for each workpiece. Furthermore, Japanese Patent Application Laid-Open No. 10-180585 discloses a technique in which a chip removing unit including a nozzle that injects pressurized fluid while making oscillating motion of two-degree-of-freedom is attached to the inside of a splash guard and the pressurized fluid is injected toward a workpiece or the upper surface of a table during machining to cause chips to drop into a chip recovery groove.
However, both of the prior art techniques described above inject liquid to a workpiece or a table during machining to cause chips that has been adhered to or accumulated on the workpiece or the upper surface of the table to drop onto the lower part of the cover, but do not wash out chips that has been adhered to or accumulated on the inside of the cover. With the prior art technique disclosed in Japanese Utility Model Application Laid-Open No. 03-026451 described above, the entire pipe to which the nozzle is attached is driven. With this, even when a plurality of nozzles are provided, the nozzles make the same motion and cannot be controlled to have individual orientations. Because the nozzles can only make motions programmed in advance, the orientations of the nozzles cannot be changed in accordance with the conditions.
None of the prior art techniques described above cannot perform individual control of liquid discharge from nozzles.